1. Field of the Invention
The present invention relates to heat dissipation assemblies, and more particularly to a heat dissipation assembly including a fastener to fasten a heat sink onto a heat generating device.
2. Description of Prior Art
Electronics technology continues to boom unabated. Numerous modem electronic devices such as central processing units (CPUs) of computers operate at high speed and thus generate large amounts of heat. The heat must be efficiently removed from the CPU; otherwise, abnormal operation or damage may result. Typically, a heat dissipation assembly is mounted onto the CPU to dissipate heat therefrom.
Most commonly, a heat dissipation assembly comprises a heat sink and a fastener for attaching the heat sink to the CPU. The fastener is stamped from a metal plate, and comprises a pressing portion and a pair of legs depending from opposite ends of the pressing portion. However, the fastener needs to be quite rigid in order to provide enough retention force for the heat sink. Engagement and disengagement of the fastener are unduly laborious, and a tool is usually required to facilitate the engagement and disengagement.
To overcome the problems of the above-mentioned heat dissipation assembly, Taiwan Patent No. 328391 discloses a different kind of heat dissipation assembly. The heat sink assembly comprises a heat sink and a clip. The clip comprises a main body and a handle. The main body comprises an elongated horizontal portion, and a pair of legs depending from opposite ends of the horizontal portion. A pair of arcuate protrusions is formed outwardly and downwardly from opposite sides of a middle of the horizontal portion. The handle comprises a pressing plate for pressing the heat sink, and a pair of symmetrical side plates extending from opposite sides of the pressing plate. Each side plate comprises a sloped top edge and a substantially horizontal top edge. The pressing plate is disposed below the horizontal portion. The side plates of the handle sandwich the horizontal portion of the main body therebetween.
In use of the clip to secure the heat sink onto a CPU, the clip is placed on the heat sink with the pressing plate contacting a top surface of a base of the heat sink. The handle is partly disposed outside the heat sink and the legs are loosely engaged with a CPU socket. The handle is pushed inwardly, and the protrusions ride on the sloped top edges and then to the horizontal top edges of the side plates. Finally, the protrusions are stopped in notches defined in the side plates. Therefore, the horizontal portion of the main body is lifted by the side plates, and the legs are resiliently engaged with the CPU socket to firmly secure the heat sink on the CPU.
However, the notches of the side plates are quite shallow. The protrusions are prone to move from the notches toward the pressing plate when the assembly is subjected to shock or vibration. The legs may loosen from the CPU socket, with the clip no longer securely retaining the heat sink. The heat sink may even become unserviceable.